UML Modeling Techniques > Activity modeling > Activity partitions > Assigning a Modeler item to an activity partition
  
Assigning a Modeler item to an activity partition
1. On the Activity Partition's Property Pages, click theOptions tab.
2. Click the Select button.
3. From the Types list, select the type of the item you want to assign.
4. Select the item you want to assign to the Activity Partition, and then click OK
Alternatively,
Drag the Modeler item to the Activity Partition.